I've seen a lot of posts on this subject but no posting of an actual filter schematic. Here's mine. It includes a de-emphasis section for flat audio response systems; omit if using pre-emphasized audio in your controller.
As John pointed out in an earlier post, the performance of the HPF in the ComSpec TS-32 leaves a bit to be desired. Yes it will strip CTCSS tones nicely, but it has a poor transient response & will "ring" around 400 Hz. This is the reason systems using this filter have a "boxy" sound. For my system I decided to use the filter in the Sigtone C1116 decoder. I redesigned the filter to cut off a bit low in frequency (210 Hz) in order to slightly improve system audio quality, since I didn't need brick-wall filtering at the higher tone freqs. that I don't use. Happy Thanksgiving everyone! Bob NO6B Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
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